Platen power drive for line spacing,vertical tabulation and form-feed spacing

ABSTRACT

A PLATEN POWER DRIVE OF LINE SPACING VERTICAL TRIBULATION SPACING AND FORM-FEED SPACING FOR USE WITH A PAGE PRINTER. A CLUTCH IS COUPLED BETWEEN A POWER SHAFT AND AN OUTPUT SHAFT TO TURN OUTPUT SHAFT A FIXED NUMBER OF DEGREES PER CLUTCH CYCLE. THE OUTPUT SHAFT IS GEARED TO THE PLATEN WHICH CARRIES THE DOCUMENT AND ROTATES THE PLATED ONE LINE SPACE PER CLUTCH CYCLE. IN ADDITION, THE OUTPUT SHAFT DRIVES AN AXILIARY SHAFT ON WHICH THERE IS SELECTIVELY PLACED A CHANGEABLE PROGRAM DRUM WHICH HAS A PROTUBERANCE FOR EACH LINE OF THE DOCUMENT. SENSING MEANS PROVIDED TO SENSE THE PRORUBERANCES AND THE SENSING MEANS IS MADE TO CONTROL THE CLUTCH ACCORDINGLY, BY ADJUSTING SELECTED PROTUBERANCES ON THE PROGRAM DRUM THE DOCUMENT, CARRIED BY THE PLATEN, MAY BE LINE SPACED OR VERTICALLY TABULATED TO ANY PRESELECTED LINE LOCATION AS INDICATED BY THE SETTING AND THE SENSING OF THE CORRESPONDING PROTUBERANCE.

United States Patent [72] Inventors Henry ,E. Smith Brockport; Donald C. Wilcox, Fairport, N.Y. [21] Appl. No. 688,441 [22] Filed Dec. 6, 1967 [45] Patented June 28, 1971 [73] Assignee The Singer Company [54] PLATEN POWER DRIVE FOR LINE SPACING,

VERTICAL TABULATION AND FORM-FEED SPACING 5 Claims, 7 Drawing Figs.

[52] U.S.Cl l97/l14,-

I 197/127;l33 [51] Int.Cl ..B41jI9/76 [50] FieldolSearch 197/114,

Primary E.taminerErnest T. Wright, Jr. Attorneys- Patrick J. Schlesinger, Charles R. Lepchinsky,

George W. Killian and Jay M. Cantor i ABSTRACT; A platen power drive for line spacing, verticai tabulation spacing and 'form-feed spacing for use with a page printer. A clutch is coupled between a power shaft and an output shaft to turn the output shaft a fixed number of degrees per clutch cycle. The output shaft is geared to the platen which carries the document and rotates the platen one line space per clutch cycle. In addition, the output shaft drives an auxiliary shaft on which. there is selectively placed a changeable program drum which has a protuberance for each line of the document. Sensing means are provided to sense'the protuberances and the sensing means is made to control the clutch. Accordingly, by adjusting selected protruberances on the program drum the document, carried by the platen, may be line spaced or vertically tabulated to any preselected line location as indicated by the setting and the sensing of the corresponding protuberance.

PATENTEUJUHZM?! 3,587,811

sum 1 OF A FIG.!

HENRY E. SMITH DONALD C. WILCOX PATENTED JUN28 |97l SHEET 2 OF 4 FIG.2

PATENTED JUN28 19m SHEET 3 OF 4 PLATEN POWER DRIVE FOR LINE SPACING, VERTICAL TABULATION AND FORM-FEED SPACING This invention relates to a platenpower drive for line spacing, vertical tabulating spacing and form-feed spacing with as sociated platen manual controls.

Typewriters and other similar printing mechanisms have been known for many years and, typically, they are provided with manual and/or automatic means for indexing the platen one or more line spaced at a time. In the prior art there has been developed form-feeding mechanisms and line finders for the indexing of continuous forms. One of the difficulties with the prior art structures was that it was difficult to adjust the structure to be used with a new form of a different length and/or on which it was desired to type at different locations.

It is an object of this invention to provide an improved platen power drive for line spacing and for vertical tabulation control and form-feed spacing with associated manual controls. It is another object of this invention to provide a formfeed control which may be readily changed to accommodate forms of different length and/or forms with information to be typed at various locations.

It is a more specific object of this invention provide selectively changeable program means for controlling and accommodating the vertical tabulating and form-feedingmechanism to a wide variety of applications.

This application-is subordinate to the copending application of Edwin O. Blodgett, Ser. No. 630,904, filed Apr. 14, 1967, and assigned to the same assignee as the present application and now issued as U.S. Pat. No. 3,426,880 and which is incorporated herein by reference. The cited Blodgett application discloses the complete details of a high speed serial character matrix page printer which is capable of printing at a much higher rate than conventional manual or electric typewriters. Other objects, features, and advantages of the present invention will appear as a detailed description thereof proceeds in the light of the drawing forming a part of this application and in which:

FIGS. 1 and 2 are a front and top view of the novel structure for rotational power drive of a printer platen to effect line spacing, vertical tabulation and a form-feed platen operation;

FIG. 3 is an end view of the structure shown in FIGS. 1 and FIG. 4 illustrates the details of the programmed drum;

FIG. 5 is a cross-sectional view along line 5-5 of FIG. 3;

FIGS. 6 and 7 illustrate the constructional details of the printer laten permitting both coarse and fine manual rota tional positioning thereof to a desired print line wherein FIG. 7 is a cross-sectional view along line 7-7 of FIG. 6.

To aid the reader who may be interested in obtaining more details concerning the printer in which the present invention is illustrated, the above-identified figures are identical to some of those used in the cited Blodgett application. More specifically, FIGS. 15 in the present application correspond to FIGS. 35-39, respectively, in the Blodgett application and FIGS. 6 and 7 of this'application correspond to FIGS. 41 and 42, respectively, of the Blodgett application. For convenience. indentical reference numbers are used in the present application and the cited Blodgett application.

The construction of the assembly 48 which rotationally drives the printer platen 13 to effect line spacing of the platen l3, tabulation spacing of the platen 13, and form-feed spacing of the platen 13, is illustrated in FIGS. 1-5. The assembly 48 is driven by a pulley 47, as explained more fully in the cited copending Blodgett application. The pulley 47, to which power is transmitted by belt 46, is rotationally supported upon a shaft 598 and drives the latter through a helical wire spring clutch 56'. The latter 56 has the same construction as the clutch 56 described more fully in FIGS. 22-24 of the cited copending Blodgett application. Components of the clutch 56' which correspond to the same components of the clutch 56 are identified by the same reference numerals primed, except that the clutch 56 is of the 90 type to effect halts of the driven shaft 598 at each quarter revolution thereof. To this end, the cylindrical housing 435 and stop which is 438' have Four spaced stop protuberances 439 and 440' engaged by the stop member 441' which is pivotally supported on pin 442' and the stop member 438 has four 90 spaced detent protuberances (not shown but similar to protuberances 450 as shown in FIGS. 22 and 23 of the cited Blodgett patent) engaged by the detent member 451' which is pivotally supported on pin 452'. Brackets 446 and 455' support the stop member 441' and the detent member 451', respectively, as more fully set forth in the cited Blodgett application. The shaft 598 is journaled by opposed walls 599 and 600 joined by end walls 601 and 602 which together form an integral assembly casting of box-frame configuration open at top and bottom. A support flange 603 is provided at the lower outside corner of the juncture of the walls 599 and 601, a thick fillet 604 of rectangular cross section is provided at the lower inside corner of such juncture, a support flange 605 is provided at the lower outside corner of the juncture of the wall 600 and 602, and the wall 602 terminates at its rearward end in a U-shaped portion 606 having upstanding trunnions 607 and 608 at the ends thereof and which are joined to the wall 599. Machine screws (not shown) pass through holes 6030 and 605a support flanges 603 and 605, respectively into pedestals 30 on base plate 19. The shaft 598 drivingly supports a cam 609 having four cam lobes, as shown in FIG. 2, with equal 90 spacings for a purpose presently to be explained. A bushing 610 secured on the end of the shaft 598 helps to position the shaft 598 in the assembly casting and to prevent excessive longitudinal motion of shaft 598.

A worm gear 611 is secured to the shaft 598 in driving mesh engagement with the pinion gear 612 secured by a gear hub 613 on a shaft 614 journaled in the assembly casting trunnions 607 and 608. A drive gear 615 secured on the shaft 614 drives the printer platen 13 through a driven gear 616 (FIG. 2) which is supported upon at and is drivingly connected to the righthand shaft 617 of the platen 13. The shaft 614 rotationally supports outer and inner U-shaped yokes 618 and 619, which are mechanically connected together for rotation in unison on the shaft 614, and drivingly supports a drive pinion 620 secured to the shaft 614 within the inner yoke 619 as shown in FIGS. 1 and 5. The outer arm 621 of the outer yoke 618 is extended to terminate in an out-turned tab 622 which may be manually grasped to pivot the yokes 618 and 619 about the shaft 614 for a purpose presently to be explained. The free ends of the inner yoke 619 carry a shaft 623 upon which an idler gear 624 is rotationally supported in meshed engagement with the drive pinion gear 620 at all angular positions of the yoke 619 on the shaft 614. The yoke 619 has a projecting end edge portion 625 which anchors one end of a tension spring 626 having its opposite end anchored by the stud 347 provided on the bracket 339 of the cast pedestal 29 secured to right hand corner flange 28 as shown in FIG. 2 of the cited reference Blodgett patent. This spring 626 biases the idler gear 624 in drive meshing engagement with the teeth 628 of a vertical tabulation programmed control drum 629 formed of a molded thermoplastic material. The control drum 629 has a configuration shown more clearly in FIG. 4. It includes a projecting end flange 630 having spaced edge serrations 631 for a purpose presently to be explained and a central hub 632 with axially projecting tongue 633 by which the drum 629 is supported upon the end of a shaft 634 (FIG. 5) and drives the shaft 634 by engagement of the tongue 633 with a radial notch 635 ofa collar 636 pinned to the shaft 634 (FIG. 5). The drum 629 is removably secured on the end of the shaft 634 by a thumb nut 637 threaded axially into the end of the shaft 634. The shaft 634 is journaled by the casting wall 602 and by the integral casting end bracket 638, is longitudinally positioned by the collar 636 and a collar 639, and has secured thereto a cam 640 as shown. As seen in FIG. 3 cam 640 has a single lobe 640'.

As illustrated more clearly in FIG. 2, the cam 609 is engaged by a cam follower 641 of an electrical contact assembly 642 having a pair of normally open electrical contacts 643 operated by the cam follower 641 to closed contact position through a leaf spring 644 and a reciprocally guided push rod 645 of electrical insulating material. The contact assembly 642 is of the type more fully shown and described in the Blodgett US. Pat. No. 2,927,158 (i.e., the cam-actuated contact assembly CC thereof) and is affixed by a machine screw 646 in vertically adjustable position on the right-hand face of a mounting block 647 secured by machine screws 648 on the end of the fillet 604 as shown in FIG. 1. During each complete rotation of the driven shaft 598, the gear ratio between the worm gear 611 and the pinion gear 612 and that between the gears 615 and 616 is such that the platen 13 is rotated through an angle corresponding to four print lines. Accordingly, the four 90 lobes of the cam 609 correspond to four line spacings of the platen l3 and each lobe of cam 609 actuates the electrical contact 643 to closed contact position each time the platen 13 is rotated one line space. The electrical contacts 643 are utilized in electrical control systems described more fully in the cited copending Blodgett application to control the energization of the electromagnet 448' at each 90 clutch position of the clutch 56 as the latter controls platen line spacing, platen tabulation spacing, and tabulation form-feed operation.

An L-shaped bracket 653 supporting a pair of electrical contacts 654 is supported on the end of the U-shaped bracket 655 (FIG. 3) pivotally supported upon a stud 656 of a rearwardly extending end portion 657 of the assembly casting wall 599. A cam follower arm 658 pivoted on a stud 659, provided on the extended end 660 of the bracket 655, carries a cam follower roller 661 which engages the periphery of the flange 630 of the vertical tab program drum 629 and is maintained in engageable relation therewith by the resilient bias of the lower contact of the electrical contact pair 654 exerted through a projecting portion 662 integrally formed as a side extension of the cam follower arm 658. The bracket 655 is normally so pivotally positioned on the stud 656 that the engagement of the cam roller 661 with the serrated periphery ofthe drum end flange 630 operates through the projection 662 normally to maintain the contacts 654 in open contact position. This positioning of the bracket 655 is accomplished by a tension spring 6211 which is anchored between a projection 6222 on the bracket 655 and the projecting end 663 of an L-shaped bracket 664 secured on the casting portion 657 and which thereby biases the yoke 655 towards rotation in the clockwise direction as viewed in FIG. 3. The ratio between the gears 620 and 624 and between the gear 624 and the tooth drum 629 is such that the spacing between the edge serrations 631 of the drum flange 630 corresponds to one line space of the printer platen 13. The land 665 between each adjacent pair of the edge serrations 631 identifies an individual print line of the platen 13, and the diameter of the flange 630 is selected to provide an integral number of such lands 665 totaling in number one more than the total number of print lines on a particular form wrapped about the platen 13. By breaking away or otherwise removing selected lands 665 corresponding to selected print lines of the platen 13, the cam follower roller 661 drops into the peripheral surface depression thereby created to permit closure of the electrical contacts 654 and this closing of the electrical contacts 654 is employed in an electrical control system to effect programmed rotational vertical tab spacings of the platen 13 as more fully described in the cited Blodgett application.

Different lengths of form wrapped about the platen 13 have correspondingly different numbers of print lines, and such change of form length is accommodated merely by changing one vertical tab programmed drum 629 with another having a correspondingly larger or smaller number of circumferential teeth 628 and a larger or smaller number of lands 665 pro vided on the flange 630 of the drum 629. More specifically, the substitution of one drum or control member 629 for another introduces two changes into the system. First, the number of land areas 665 on the flange 630 is altered and second, the number of teeth 628 of the gear surface is altered. In the case of the teeth 628, the pitch must remain constant from one drum 629 to the next as the teeth 628 must mesh with those of idler gear 624. Accordingly, the radial distance of each tooth 628 from the center of the drum 629 varies with the total number of teeth 628. A reduction in the number of teeth 628 causes a reduction in the radial distance to which reference has been made. It is obvious that the reduction of the number of teeth 628 will result in a full revolution of the associated drum 629 in response to a reduced angular rotation of platen 13. Conversely, an increase in the number of teeth 628 will require an increased angular rotation of platen 13 to produce a full revolution of associated drum 629. By selecting a drum 629 having an appropriate number of teeth 628, which constitute the drive element of drum 629, it is possible to provide any desired predetermined individual proportional rotational relation between the platen l3 and the drum 629. It should be understood that the diameter of flange 630 is substantially constant irrespective of the number of teeth 638. However the pitch of areas 665 on flange 630 is adjusted to be equal to the angu;ar rotation of control drum 629 in response to the angular rotation of platen 13 when rotating one line space. A change from one drum 629 to another is accomplished by manually grasping the tab 622 and pivoting the yoke 619 counterclockwise as seen in FIG. 3 to disengage the idler gear 624 from the teeth 628 of the drum 629. A pin 666 carried by the lower end of the yoke arm 621 cooperates at this time with a cam surface 667 formed on the upper edge of the outer arm of the bracket 655 to pivot the latter also counterclockwise as seen n FIG. 3 and thereby space the cam roller 661 from the flange 630 of the drum 629. A small depression 668 at the end of the cam surface 667 provides detent engagement with the pin 666 to maintain the yoke arm 621 as thus angularly positioned. The thumb nut 637 is then manually unscrewed to permit the old vertical programmed drum 629 to be slipped off the shaft 634 and a substitute drum 629 to be slipped onto the shaft 634 after which the thumb screw 637 is manually replaced to secure the new drum 629 in position on the shaft 634. Thereafter the tab 622 is manually grasped and the yoke arm 621 rotated clockwise as seen in FIG. 3 once more to engage the pinion gear 624 with the teeth 628 of the new drum 629 and to move the cam roller 661 into engagement with the periphery of the flange 630 of the The drum 629.

Since one complete revolution of the drum 629 corresponds to one print line more than the total number of print lines on a given length of form wrapped about the platen l3, and since the drum 629 drives the shaft 634 and with it the cam 640, it will be evidenced that one complete revolution of the drum 629 corresponds to rotation of the platen 13 from a given print line of one form to the same print line of a succeeding form. The single lobe 640' of the cam 640 thus enables form-feed rotational drive of the platen 13 and to this end the cam 640 operates a pair of normally open electrical contacts 669 (FIG 3) through cam follower 670 pivotally supported together with the contacts 669 on a L-shaped bracket 671 secured on the outside forward end of the assembly casting wall 602 as shown in FIGS. 1 and 3. The electrical contacts 669 are utilized in the electrical control stem more fully described in the cited copending Blodgett application to control form-feed rotational drive of the platen 13.

It was explained above that the gear 616 is supported upon and is drivingly connected to the right-hand shaft 617 of the platen 13. This driving connection is such that the gear 616 may be manually displaced axially of the shaft 617 to disengage the gears 616 and 615 and permit manual rotation of the platen 13 to the approximate position ofa desired print line on the form wrapped about the platen 13. Thereafter the gears 616 and 615 are allowed to reengage and a further manual control enables manual rotation of the platen 13 more precisely to the desired print line of the form. This platen position control has conventional construction familiar to those acquainted with such mechanisms and illustrated in FIGS. 6 and 7. The platen shaft 617 is provided with a reduced diameter shaft end portion 675 upon which a sup-shaped member 676 is positioned and secured by a pin 677. The gear 616 is rotationally supported on the member 676 and is secured by machine screws 678 to a concentric ring clutch member 679. Member 679 as a short internal radial flange 680 extending towards shaft 617 and terminating in an internal wall 680 which is slightly skew with respect to the axis of shaft 617 and which has a succession of closely spaced fine clutch teeth 6802 all as shown in FIGS. 6 and 7. A pair of radially projecting arms 681 of rectangular cross section extend through radial end slots 682 of the member 676 and are movably supported by a hub 683 upon the shaft portion 675. The arms 681 extend towards internal wall 6801 and have rounded and tapered ends provided with fine clutched teeth which mate with the teeth 6802 of the flange 680 of the ring clutch member 679. A helical wire spring 684 enclosed by the member 676 biases the arms 681 to engage the clutch teeth thereof with the clutch teeth 6802 of the ring member 679. The shaft end portion 675 is provided at its inner end with an elongated longitudinally extending radial slot 685 and is axially bored 679. to receive a push rod 686 having a finger-push knob 687 secured at its outer end. A pin 688 projects through the slot 685 of the shaft portion 675 and connects the inner the push rod 686 with the hub 683 so that axial movement of the push rod 686 by finger pressure applied to the knob 687 moves the arm 681 against the bias of the spring 684 to disengage the clutch teeth of the arms 681 from the clutch teeth 6802 of the internal flange 680 of the clutch ring member 679. The platen 13 may now be manually rotated by a knob 689 which is supported by a knob sleeve 690 on the end of the shaft end portion 675 and is mechanically connected to the latter by machine screw 691 extending through an elongated longitudinal slot 692 the sleeve 690 and received in an internally threaded aperture 693 of the shaft end portion 675. Such rotational adjustment of the platen 13 may be in incremental steps according to the pitch or spacing of the clutch teeth on the arm 681 and on the'internal flange 680 of the ring member 679, the platen 13 in adjusted position being then locked to the platen drive gear'616 by release of finger pressure on the knob 687 to reengage the clutch teeth of the arm 681 with the clutch teeth 6802 of the flange 680 of the ring member 679.

To disengage the platen gears 616 from the drive gear 615 and thus permit manual rotation of the platen 13 to the approximate position of a desired print line of a form wrapped about the platen 13, a pair of radial arms 694 of rectangular cross section are positioned within the radial end slots 682 of the member 676. The arms 694 are slideably supported on the shaft end portion 675 by a hub 695, and have sufficient arm lengths to overlap the outer end of the ring member 679. A sleeve 696 is slideably positioned on the shaft end portion 675 between the hub 695 and the end of the knob sleeve 690. Upon manually pushing the knob 689 toward the platen 13 to a position indicated in broken lines in which the machine screw 691 engages the end sleeve aperture 692, the sleeve 696 effects corresponding movement of the arm 694 longitudinally on the shaft end portions 675. The arms 694 engage and correspondingly move the ring member 679 and the gear 616 axially on the member 676 to a gear position indicated in broken lines where it is disengaged from the gear 615. The ring member 679 in so moving effects compression of the spring 684 through engagement of the ring flange 680 with the arm 681. Subsequent manual rotation of the knob 689 is transmitted through its sleeve 690 and the machine screw 691 to effect corresponding rotation of the shaft end portion 675 and thereby of the platen 13 to the approximate position of the desired print line of the form, such positional rotation of the platen 13 being in steps according to the pitch teeth of the gears 615 and 616. The platen 13 is then locked in this adjusted position by manually pulling the knob 689 away from the platen 13 to permit the compression spring 684 to operate through the arms 681 and the ring member 679 and restore the gear 616 into meshed engagement with the gear 615, the arm 694 and sleeve 696 returning with the ring member 679 to the positions which they occupied prior to the platen adjustment eriod.

Fl 3 also illustrates the relationship between the platen l3 and the printing assembly more fully described in the cited copending Blodgett application. More specifically, the print head moves longitudinally along guide rail 153. Base plate supports the funnel housing 178 and nose block 189 containing the print wires, all as more fully described and illustrated in the cited Blodgett application.

FIG. 6 also illustrates part of the pin feed mechanism more fully described in the cited Blodgett application. More specifically, there is shown a part of the platen 13, the paper bail rod 759 and its arms 758 and flanges 762 of the paper hold down shoes which are apertured for pivotal support on the bail rod 759 and held in place by clips 763. Slots 765 in the paper hold down shoes accommodate feed pins 764.

While there has been shown and described what is considered at present to be the preferred embodiment of the invention, modifications thereto will readily occur to those skilled in the related arts. For example, in another structure a control element could be provided which revolves only a half revolution per form; or vertical tabulation could be stopped in response to the presence of a tooth rather than in response to the removal of a tooth. It is believed that no further analysis or description is required and that the foregoing so fully reveals the gist of the present invention that those skilled in the applicable arts can adapt it to meet the exigencies of their specific requirements.

We claim:

1. A typewriter platen rotational drive system comprising:

a. a source of driving power;

b. a first gear train connected to said platen;

c. a clutch connected to said source and said first gear train;

d. electromagnetic controlling means for controlling said clutch to engage and disengage the power source from said first gear train 1. said electromagnetic controlling means comprising a second gear train;

. first switch means operated by said first gear train ,for operating said electromagnetic controlling means to drive said platen through a first preselected angle;

. second switch means operated by said second gear train for operating the electromagnetic controlling means to drive said platen through a second preselected angle;

g. a selectively changeable program disc integral with one of the gears of said second gear train;

h. third switch means operated by said program disc for operating said electromagnetic controlling means to drive said platen through a third preselected angle; and

i. an idler gear oscillatably mounted about a single fixed axis for engagement and disengagement with said one of said gears of said second gear train and another gear of said second gear train whereby various program discs having gears with different numbers of teeth can be substituted in said second gear train without changing the other gears in said second gear train.

2. A drive system as defined in claim 1 further including means for locking said idler gear at one end of the path of oscillation disengaged from said one of said gears and salD another gear.

3. A drive system as defined in claim 2 further including resilient means biasing said idler gear into engagement with said one of said gears and said another gear.

4. A drive system as defined in claim 1 wherein the first switch means operated by the first gear train comprises a cam having four lobes and a pair of contacts operated by the lobes of the cam.

5. A drive system as defined in claim 4 wherein said second switch means operated by said second gear train comprises a cam having a single lobe and a pair of contacts operated by the single lobe. 

